Field of the Invention
The present invention relates to a still camera that has an optoelectric transducer arrangement with a sensor surface in the image plane whereby the sensor surface is smaller than the area to be imaged in the plane, and whereby the transducer arrangement is mounted parallel to the image plane and controlled, driven, and slidable therein.
The present invention relates to a still camera that has an optoelectric transducer arrangement with a sensor surface in the image plane whereby said sensor surface is smaller than the area to be imaged in said plane, and whereby the transducer arrangement is mounted parallel to the image plane being controlled, driven, and slidable therein.
Optoelectric transducer arrangements, such as CCD arrays, are relatively expensive components in digital cameras. This is especially the case when they are designed by having a relatively large surface. In digital cameras with a relative large area to be imaged in the image plane, it is known therefore to provide optoelectric transducer arrangements whereby their sensor surface is smaller than the area to be imaged in the image plane. The transducer arrangement is driven by means of mechanical stage guides (stage with X and Y movements) and moved time-sequential over individual segments of the area to be imaged in the image plane. The optoelectrically converted image segment is stored at each position of the transducer arrangement. These image segments are subsequently combined again electronically into a complete image.
The process of precise mechanical stage guiding for exact mechanical shifting and positioning of the optoelectric transducer arrangement with coordinate drives that may be driven independently is constructively extremely complicated.
It is the object of the present invention to provide a still camera of the type mentioned in the beginning with which the transducer arrangement may be positioned over the image segments substantially simpler and more cost-effective without loss of precision in positioning.
In view of the first object aspect according to the invention, the object is achieved in that the optoelectric transducer arrangement is rotatably mounted about an axis that is perpendicular to the plane of the image.
Through this process it is achieved that the transducer arrangement, which is now rotatably mounted in the most simple way, may be rotated sequentially by means of one single drive over various segments of the area to be imaged in the image plane.
With this process there has to be basically considered that because of the pivoting movement of the transducer arrangement, the image segments appear sequentially pivoted on the sensor surface of the transducer arrangement and they are correspondingly converted optoelectrically as they are positioned. With this innovative process it is therefore proposed that the electric output of the transducer unit is actively connected with an electric signal that represents the converted image area, as well as with a signal that identifies the rotational position of the transducer arrangement, and with inputs of a computing element, which converts the signal representing the image area in accordance with the signal identifying the rotational position, into a signal representing the predetermined two-dimensional alignment of the aforementioned image areaxe2x80x94in relation to the camera.
Thereby, the computing element does not change the electrically supplied image area information, but turns back by computingxe2x80x94essentially based on a coordinate transformationxe2x80x94the electrically supplied image information in a predetermined two-dimensional alignment in such a manner that each electric image area signal represents one image area in the same alignment, independent from the mechanical rotational angle.
Even though it is absolutely possible to rotatably mount the transducer arrangement relative to an axis of rotation that lies outside the area to be imaged in the image plane, it is preferably proposed that the optoelectric transducer arrangement be rotatably mounted relative to the optical axis. Thereby there is in one instance the possibility to scan the area to be imaged sequential in segments with an optimal small sensor surface of the transducer arrangement and thereby the mentioned electronic rotation compensation becomes very simple on said computing element.
In a second and currently preferred solution approach, according to the invention, the optoelectric transducer arrangement is guided by means of a cam/curve arrangement parallel to the image plane and with consideration to its shifting characteristics. Thereby it is made basically possible to guide the optoelectric transducer arrangement in an arbitrary movement path sequentially over the area to be imaged in the image plane, to scan said area to be imaged, and to realize this furthermore with one single controlled drive.
In a highly preferred embodiment of the innovative still camera, taking the secondly mentioned aspect into consideration, the optoelectric transducer arrangement is guided exclusively translatory relative to its shifting characteristics by means of the cam/curve arrangement. This has the considerable advantage thatxe2x80x94based on the purely translatory shifting of the optoelectric transducer arrangementxe2x80x94no relative rotation of the image occurs on the sensor surface of the transducer arrangement and thereby no computed rotation or pivoting compensation is to be expected. In relationship to the thereby performed movement of the optoelectric transducer arrangement, the advantage of a mechanical stage movement guide is maintained.
In another preferred embodiment of the innovative still camera, referring to the second (solution) approach, the optoelectric transducer arrangement is guided by means of an annular cam/curve arrangement of the same effective radii.
If there are only two of the cam/curve arrangements providedxe2x80x94and the optoelectric transducer arrangement is guided along a straight line via camsxe2x80x94then it is of course guaranteed that the two cam/curve arrangements are imperatively and simultaneously driven in the same rotational direction. This may be prevented, for example, by movement coupling or by preventing that the cam/curve arrangement is driven to its dead end.
In a preferred embodiment of the innovative still camera under all aspects, the sensor surface of the optoelectric transducer arrangement has at least one approximate rectangular or square surface.
On the innovative still camera, under all its aspects, there is furthermore preferably provided one single, guided rotating drive, which is actively connected to the optoelectric transducer arrangement and stationary relative to the camera.
The invention as described below with reference to drawings.